Keep-alive anode.



D. C. DAVIS.

KEEP ALIVE ANODE.

APPLICATION FILED MAY II. 1914.

1,222,537. Patented Apr. 10,1917.

' INVENTOR WC 6.

ATTORNEY UNITED STATES PATENT OFFICE.

DAVID C. DAVIS, 01' SWISSVALE, PENNSYLVANIA, ASSIGHOB 1'0 WESTINGHOUSEELEG- TRIC m IAI'IIIIIAGTIITB. IN"! CODA, A CORPORATION 01'PENNSYLVANIA.

KEEP-ALIVE ANODE.

Specification of Letters Patent.

I Application fled Kay 11, 1914. Serial Io. 087,785.

Toallwhomit concern:

Be it known t at I, DAVID C. DAVIS a citizen of the United States, and aresident of Swissvale, in the county of Allegheny 6 and State ofPennsylvania, have invented a new and useful Improvement in Keep-AliveAnodes, of which the following is a specification.

My invention' relates to vapor electric apparatus and more specificallyto the solid electrodes employed therein, and it has for its object toprovide an electrode which will operate to give a stable are for a longperiod of time without artificial cooling.

In the construction of vapor electric apparatus, especially mercury-arcrectifiers of the heavy-current type, it has been customary to constructthe main anodes of hollow steel and to provide them with fluid coolingmeans in order to prevent excessive heating. The small anode employedfor the maintaining or keep-alive arc has not been cooled, however, buthas been constructed of a small rod of refractory material such, forexample, as tungsten. This rod slowly melts or volatilizes until, atlast, the path for the keep-alive arc is so long that it is necessary tosupply an excexive amount of power thereto in order to maintain therectifier in operation. By my invention, simple and economical means areprovided for feeding forward the tungsten rod in accordance with thewasting away thereof, and the keep-alive arc is maintained at the mostfavorable length and power consumption.

In the acompanying drawing, Figure 1 is a view, partially in section andpartially in elevation of a rectifier embodying my invention; Fig. 2 isa sectional view of the electrode employed in Fig. 1; Fig. 3 is a sideview, partially in section and partially in elevation, of the electrodeemployed in Fig.

. 1; Fig. 4 is a view, in section, of a modified form of electrode; Fig.5 is a side view, in elevation, of another form of electrode; Fig. 6 isa side view, in section, of the electrode rest shown in Fig. 1, and Fig.7 is a view, in plan of the rest shown in Fig. 6.

An evacuated container 1 of any suitable material, such, for example, assteel, is provided with a main anode 2 and a liquid cathode 3. The anode2 is preferabl water cooled by means of tubes 23 and 24. urrent issupplied to the anode by a conductor 4 and taken from the cathode bymeans of the container wall and a conductor 5. The cathode 3 is composedof any suitable reconstructing material, such, for example, as mercury.A conducting member 6 projects through the cover of the container 1 andis sealed thereinto and insulated therefrom by any suitable means, suchas a joint 7. The inner end of the member 6 is provided with a tubularextension of conducting material provided with pins 9, preferably threein number, adjacent to its lower end. A member 10 of refractorymaterial, such, for example, as quartz or lava, is mounted on these pinsby an ordinary bayonet joint, as is clearly shown in Figs. 6 and 7. Ared 11 of refractory conducting material, such, for example, astungsten, is inserted within the conducting extension 8 and is forged orcold rolled about a fin 12 of a material having a relatively low meltingpoint, such, for example, as iron, copper or zinc. The lower end of thefin is some distance from the lower end of the rod 11 and rests upon theupper surface of the member 10, while the rod 11 extends into theneighborhood of the cathode 3. A spring member 13 serves to keep the finmember 12 in close contact with the member 10 and also serves to conductcurrent to the refractory rod 11. Direct current is supplied to themember 6, and thence to the rod 11, by a conductor 14. A refractoryinsulating shield 25 surrounds the members 6 and 8 and protects the samefrom the main arc.

In the operation of my device, any suitable source of direct current isconnected between the conductor 14 and the conductor 5, and maintains anare between the lower end of the rod.11 and the cathode 13, maintainingthe latter in an active condition. If a source of alternating current beconnected between the wires-4 and 5, positive waves will be allowed topass, while negative waves will be stopped, as is well known in the art.

Since it is a difiicult task to forge a refractory material, such astungsten, about a fin as shown in Fig. 2, I may groove my tungsten asshown at 1516 in Fig. 4, and crimp a metallic member 17 into thegrooves. The member 17 may be of any suitable material having arelatively low melting point and will, by its engagement with the rodfor a considerable length, provide ample holding power for all practicalpur oses. Fig. 5 illustrates still another form 0 electrmlr wherein arefractory rod 20 is clamped to a rod '21 of relatively low meltingpoint 21 by an ordinary band clamp 22.

I am aware that it is old in the are lamp art to mold carbon andcompositions around fins of low meltin point and, accordingly, I do notclaim this idea broadly but have restricted my claims to themodifications necessary to apply this method of electrode feeding to thevapor arc rectifier.

I claim as my invention:

1. In vapor electric apparatus, the combination with an evacuatedcontainer, of a liquid electrode therein, a consumable solid electrodeadjacent thereto, and means for automatically compensating for theconsumption of said solid electrode.

2. In vapor electric apparatus, the combination with an evacuatedcontainer, of a liquid electrode therein, a solid electrode, comprisinga substantially vertical rod of refractory conducting material, havingits lower end adjacent to the liquid electrode, means for maintaining anare between the two electrodes, and means for automatically feeding therefractory electrode downwardly in accordance with the consumptionthereof.

3. In vapor electric apparatus, the combination with an evacuatedcontainer, of a liquid electrode therein, a solid electrode, comprisinga substantially vertical rod of refractory conducting material, havingits lower end adjacent to the liquid electrode, and means forautomatically maintaining an arc of substantially constant lengthbetween the two electrodes.

4. In vapor electric apparatus, the combination with an evacuatedmetallic container having an opening in the wall thereof, of aconducting member passing through said opening, an insulating gas-tightjoint between said member and the wall of the container, a liquidelectrode within the container, and a consumable solid electrode adjacent thereto,said solid electrode being carried by said conductingmember and being automatically adjustable with relation thereto inaccordance with its rate of consumption.

5. In vapor electric apparatus, the combination with an evacuatedcontainer having an opening therein, of a conducting member passingthrough said opening, a tubular extension on sand conducting memberwithin the container, a refractory conducting rod projecting from saidtubular member, a feed member of comparatively low melting point withinsaid tubular member and attached to the refractory rod, and a refractorystop member carried by the end of the tubular member and acting as arest for the end of the feed member.

6. In vapor electric apparatus, the combination with an evacuatedcontainer having an opening therein, a conducting member passing throughsaid opening, a tubular extension on said conducting member within thecontainer, a refractory conducting rod projecting from said tubularmember, a feed member of comparatively low melting point within saidtubular member and attached to the refractory rod, of a refractory stopmember carried by the end of the tubular member and acting as a rest forthe end of the feed member, and a refractory insulating sleeve shieldingsaid conducting member and the tubular extension thereof.

In testimony whereof, I have hereunto subscribed my name this 28th dayof April,

DAVID C. DAVIS. Witnesses:

B. B. Hmss, M. C. Mnnz.

